Surfacing Welding Wire in the most commonly encountered problem is cracking, to prevent cracking of the main method is: 1,Aluminium Alloy Welding Wire preheating before welding, control layer temperature, slow cooling after welding. 2, post-weld stress relief heat treatment. 3, to avoid the multi-layer welding cracking, low hydrogen welding electrodes. 4, if necessary, the surfacing layer between the base material and surfacing of transition (carbon equivalent, high toughness electrodes).
Because cast iron welding high carbon content , inhomogeneity , low intensity, poor plasticity , belonging to poor weldability of the material , the welding process can easily produceHealth crack ; cooling rate after welding fast, easy to produce white tissue, causing
Cutting difficult. Welding andAluminium Welding Wire g of cast iron , to achieve satisfactory results, you must pay attention to "one-third material , seven craft " , not only toSelect the electrode, and the use of suitable welding method is particularly important.We recommend the following welding process, welding and repair welding of cast iron as a reference :
1, first clear the welded parts of the sludge, sand , water, rust and other dirt ; for a long period of high temperature steam iron castings working environment , but alsoTo clear the surface of the carbon layer and the oxide layer is depleted .2, according to the shape of the welded parts , defect type , for open groove , playing pool for the hole and modeling, and other preparatory measures .3 , the need for cold welding of the workpiece, preheated 500-600 â„ƒ or so, choose the appropriate current , continuous welding , the welding procedure remains the pre-Hot temperatures , immediately after welding powder Aluminum Flux Core Welding Wire insulation materials , allowed
Slow cooling , in order to improve their crack resistance and processability .
4, for cold welding workpiece to prevent excessive base metal melting , chilling tendency to reduce and prevent excessive heat concentration , causing too much stress , should beLow current , short arc welding narrow channel ( each bead length is generally
No more than 50mm). Immediately after welding, hammering the weld to prevent cracking stress relaxation , the temperature dropped to below 60 â„ƒ and then welded one .5 , when the attention crater crater fill , to prevent cracking at the closing arc